For a case where a semiconductor device such as MMIC (Monolithic Microwave Integrated Circuit) is mounted on a high-frequency circuit board, when a conductive wire such as a bonding wire is used to achieve connection for the mounting, an inductance component will arise depending on the line length of the conductive wire. The higher the frequency is, the more significant deterioration in transmission characteristics is due to this inductance component. In view of this, it has been customary to establish connection with a conductive wire such as a bonding wire that is as short as possible in a high-frequency region. There is a technique to place a semiconductor device inside a cavity formed in a high-frequency circuit board, and establish connection with a signal line around the cavity. This technique is described in, for example, Japanese Unexamined Patent Publication JP-A 2001-148457. In addition, there is a technique to cancel out impedance mismatch resulting from the inductance component with a newly introduced capacitance component. This technique is described in, for example, Japanese Unexamined Patent Publication JP-A 2007-95838. However, in the foregoing techniques, the resultant inductance component and the introduced capacitance component can vary even with a slight dimensional change. After all, in the foregoing techniques, high dimensional accuracy is required, and the problem is that proper matching becomes difficult at higher frequencies or that a band of frequencies at which matching can be achieved is narrow.
The invention has been devised in view of the problems associated with the conventional art as mentioned supra, and accordingly an object of the invention is to provide a high-frequency module capable of easy connection of a high-frequency circuit by means of a conductive wire.